GRAND PRAIRIE (CBSDFW.COM) – After nearly a week of searching for suspects, the driver believed to be responsible for hitting and killing a 6-year-old boy in Grand Prairie turned herself in to police on Tuesday morning. Tammy Lowe and her husband walked into the police headquarters, authorities said, looking very distraught and appearing as though she had not slept in days.

Lowe was a seventh-grade teacher at Adams Middle School in the Grand Prairie Independent School District. According to district spokesman Sam Buchmeyer, she resigned Tuesday morning before going to the police. “Left a handwritten resignation on the principal’s desk early this morning,” he said. Lowe has been an employee of the school since 1996. Buchmeyer added that she had been on campus since the hit-and-run took place, but was acting “not normal.”

John Raidy was struck and killed by a hit-and-run driver on January 24, while walking ahead of his mother, who was pushing his sister in a stroller. The boy had just purchased some candy at a nearby store and was crossing the street when the suspected driver ran a red light. The boy was carried on the hood of the car for about 300 feet before falling off. The driver sped away, and Raidy’s mother saw the whole thing. A woman passing by tried to save the child, but was not successful.

Police analyzed surveillance video and interviewed witnesses, and identified the suspect’s vehicle as a 2008 Toyota Yaris — the same type of car that Lowe drives. That vehicle was taken into police custody on Tuesday.

The 53-year-old suspect was “very forthcoming with information,” according to Det. Lyle Gensler with the Grand Prairie Police Department, telling investigators that she panicked after hitting the child and was too scared to stop her vehicle. Lowe has been charged with failing to stop and render aid, and is being held on a $100,000 bond. Police said that she will face additional charges, including one for manslaughter.

Lowe’s older sister contacted CBS 11 News on Tuesday night to talk about the arrest. Netha Morris now lives in California after growing up with her sister and brother in the McKinney area. The brother now lives in Van. Morris said that she is just mystified by the entire ordeal. “She dedicated her entire life to children,” Morris said of Lowe. “She’s never done anything to hurt people.”

Morris cannot imagine how something so terrible could have ever happened, adding that her sister does not even drink. “She’s never done anything wrong, ever. She’s one of the sweetest, kindest people I know,” Morris told CBS 11 News. “I know what she did was wrong, but she’s not the kind of person who should be in jail.”

When asked why it took so many days for Lowe to step forward, Morris offered no answers. “I don’t know why it took as long as it did, but she is the kind of person who has a conscience,” Morris said. “She’s a kind human being that made a lapse in judgment.”

Meanwhile, the child’s grandfather told CBS 11 News that he is both relieved and devastated by the arrest. “It’s going to be a healing process as far as forgiveness,” said Steven Raidy, “but the woman did something right, even though she did something terribly wrong to our grandson.”

“I would like for this woman to know what she’s done to this family,” Steven Raidy added. “What this woman single-handedly did was totally wipe out generations and generations of a family.”

The funeral for 6-year-old John Raidy will be held Wednesday at Laurel Land funeral home in Dallas. A public viewing is scheduled from 10:00 a.m. to 11:00 a.m. with the memorial service at noon. A private burial will follow.